Safety device for sewing machines



Aug. 31,1943. M. MCCANN 2,328,527

SAFETY DEVICE FOR SEWING MACHINES Filed March 31, 1942 ail um n lz chael0720 @ann Gum;

Patented Aug. 31, 1943 SAFETY mavrcn FOR saw ng MAQHINE Mi hae M flann Oo rk, Ne X-i s sisn r t The Sin e Manu a na y, Eli abeth, 3,, acorporation of New Jersey Application March 31, 194-2, erial N 4 6,911

2 Claims.-

This invention relates to improvements in sate.- ty devices andparticularly to safety devices which are adapted to be used inconnection with sewing machine stop-motion mechanisms.

The object of the present invention is to prevent the repetition of asewing machine stitching cycle in the event the operator inadvertentlymaintains the stop-motion control pedal depressed.

A further object of the present invention is the provision of animproved safety device in the form of an attachment which may beinexpensively constructed and readily applied to substantially any ofthe common types of sewing machines using a stop-motion mechanism,without the necessity of complex adjustment.

"The foregoing objects, and others ancillary thereto, have been attainedby the provision of an improved safety attachment including a supportingbracket carrying a pair of reciprocatory rods and a latch member carriedthereon adapted to be secured to a sewing machine frame whenever asafety device i required and to be readily removable therefrom when sucha unit is no longer desired.

The invention, both in structure and in operation, as well as additionalobjects thereof, will be best understood from the fo llowing descriptiontaken in c nj c on w th th om an ng drawing, in which:

Ei 1 i a .fron nerspective View o th present attachment, with thecover-plate removed, applied to .a sewin machine.

Fig. 2 is a side View of the attachment with coverplateremoved.

Fig. 3 is a front view of thedevice as shown in Fig. 2.

Fig. 4 is a horizontal section view taken substantially along line-.4?4,of Fig. 3.

Fig. ,5 is a front view of a o t o o theattachment in starting position.

Fig. 6 is an enlarged perspective view of ,the latch member and itssupporting block.

Fig. 7 is a perspective view of the coverplate.

Referring to the drawing J represents asewing machine frame in which ,isjournal ed longitudinal y thereof the usua ma -s aft 1-1 i em which :isderived, throu h the usua o erat v connections, the reciprocatingmovements of ,a needle, not' herein shown.

The stop-motion mechanism -of the present machine is substantially thesome as that shown in the United States patent to W. L. Barron, We.

1,093324'1, .o'f npril lz i, 1914. {upon theireazrward por ion at the maia-sha .4 l ar meuot d th test see le sc ca lers was '3, The ste pingamM is a so m lieteel up n nd ac -ates o ro at with he ha t H.- 9mm? nwith the stepw se-cam 4 s he P un er-he is me; tee! within the swi gingte -le er 1. fulcrumed with n the s tted bos :2 c bracket U :Ei QPrK WIl the be t shipper a m t8- Moante even h a yeia Pin 29x01 the racket-armH is the sti ma! shi t-1? ver or operative 2! or ti tin the step lever16 in oppo ition t assay n 2. to sh t driving belt, ne herein chews -romthe lease p ey is to the ti ht pul ey and di en a e the plungerebar l5irom the to ing-cam it.

h p il v r L6 isde e-me r nnin h0- ion by the usual latch means 3 whi his adapted to thus retain the S.tapr ieiwr u ning position until thestitching cycle is terminated at which time the stop-lever is released,and up: der the pressure .of the spring :22 shit-ts outwardly to engagethe .p unse ar 5 with the stopping-cam it, all in the -.us.ual manner.

It may therefore be understood that when the shiftslever 21 is ,moveddownwardly 11,13 the operator,-the stoprieyer i6 is swung inwardlythereby throwing the machine into operation. As hereinabove noted, thestopalever i6 is held latched in this position .until it isautomatically released at the end of the stitching cycle.

In a high speed machine of the present {type which is adapted forproducing groups of tack: ing stitches and the like, only .a few secondselapse between the starting of the machine and the completion of onestitch-group. It frequently :happens therefore that the operator, bycontinl ips t held the tre le zma me press d re ent t lesn ia .22 o he lm promptly moving the stop-lever it into stopping p sit n there y l -stin i d e t ve w rk or i he br kage e mach n a ts. Th use o th p esentseie y de ice o v at s th e fi ea iy.

As ote abov th gsiae wle e J5 i p ve el'ly mounted in the outwardpreieet a em s eties boss 24 to which a lflange :25 is mounted lay meansof screws one of .them being designated by number {2-6. 'Pi vptallycarried :by :fiange -25 :by means of a bolt M is a lug 2'3whichproje'cts from the rear portion of the supporting bracket 2 9. ahbel '21 cla es t ough apertu es 1 a d 57 p id d espe t e y th flange ,25and the ce #1 {E s scrape -t cs rac com r s s e substantially C-shapedmember the projecting arms and 3| of which are spaced from and are inparallelism with each other.

The arms 33 and 3| function as bearing members in which are slidablyreceived the parallel first and second rods 32 and 33. The second rod 33at its upper end normally projects above the upper portion of thebracket, and is pivotally connected to a link which in turn is similarlyconnected directly to the stop-motion shift-lever 2|. The first rod 32at its lower end normally projects below the lower portion of thebracket and is connected to the upper end of a chain 35 which normallyis connected to the usual stopmotion control lever or pedal, not hereindis-.

closed.

Pivotally mounted in spaced positions upon the upper portion of thefirst rod 32 is a bifurcated latch-lever 33 which is shiftable about thelongitudinal axis of the rod and restrained from endwise movementthereon by means of a block 31 embraced by said latch-lever and securedto the rod by means of the set-screw 38. Secured upon the latch-lever 36by means of a screw 39 is a leaf spring 40 one end of which engages theblock 31 to force the latch-lever against the second rod 33 thereby tooverlie and engage an abutment member 41 carried by rod 33 and maderigid thereto by means of a set-screw 42. Downward movement of the firstrod 32 will, therefore, because of this latch-lever and abutmentengagement, actuate the second rod 33 also in a downward direction.Surrounding the lower portion of rods 32 and 33 are coil compressionsprings 43 and M which constantly urge the respective rods upwardly. Thelower ends of springs 43 and 44 engage the bearing member 3! and theupper ends of the springs respectively engage the base of thelatch-lever 33 and the abutment member During the downward movement ofthe rods, as actuated by a pull on chain 35, the latchlever 36 engagesthe slanted cam surface 45 of a stationary trip-member 4B which is fixedto the bracket 23 by means of screws 41. Further downward movement ofthe rods will permitthe cam.- surface to turn the latch-lever 33 aboutthe longitudinal axis of the first rod in opposition to its spring 40until it rides off the abutment member 4|, whereby the second rod isreleased from further downward motion and it returns to its normallyraised or starting position under the action of its coil-spring 44. I

Figs. 2 and 3 disclose, in solid lines, the attachment the moment thatthe latch lever' 3B first, engages the trip-member M and in brokenlines, the relative positions of the component parts the moment afterthe latch has been opened thereby permitting the rod'33 to move to itsstarting position. I

It is to be understood that the initial downward movement of themanually operable chain 35 shifts both rods 32 and 33 downwardly inunison and consequently actuates the shift-lever 21! to start themachine, and when the two rod members are released from each other, asdescribed above, the stop-motion mechanism will automatically be freedfrom its manually operable chain 35 so that it may unfailingly stop themachine at the end of the sewing or machine operation. Upon release ofthe chain 35 by the operator, the first rod is raised by its spring 43to its normal or starting position, as shown in Fig. 5,

in which it again is re-connected to the second arm member. 1

When the stop-lever I6 is shifted into starting position by a downwardmovement of the shiftlever 2| it engages the latch member 23 whichretains the stop-lever in this position until the stitching cycle isterminated at which time the stop-lever is released under pressure ofspring 22.

Downward movements of rod 32 is limited by a nut 33 threaded upon thetop portion thereof and its upward movements are arrested by means of alug 49 secured upon the bottom portion thereof. Upward movements of rod33 is limited by a nut 38 threaded upon its lower portion.

In order to properly enclose the operating mechanism of the presentdevice a cover-plate 5| is provided which is adapted to be slidlengthwise over the bracket 29 and to be retained thereon by means ofits narrow head 52. In the preferred form of the device this cover-plateis constructed of a resilient sheet-metal which permits the cover-plateto be readily snapped over and removed from the bracket 29.

To attach the safety device unit to a sewing machine the user need onlysecure the flange 25 to the machine boss 23 by means of screws 26 andthen connect the link 34 to the shift-lever 2| by means of a pivot pin53. To make the safety device operative, .the chain 35 may be suitablyconnected to the usual stop-motion treadle.

From the above description it is obvious that this safety device isreadily adaptable to substantially all sewing machines which areprovided with stop-motion mechan sms. Likewise, it will be apparent thatthe device may be readily placed on and removed from operative positionby a few simple hand movements, while at the same time, it provides acompact and efficient machine actuating device. It is also of particularimport to note that the component parts of the present invention aredesigned so that a most simple and rugged construction results.Furthermore, the device requires no expensive machining operations inits production as the parts thereof may be readily cast or pressed intotheir final form.

Having thus set forth the nature of the invention what I claim hereinis:

1. In a safety device of th class described, comprising, a bracket,'afirst and a second rod disposed in parallelism with each other andmounted for endwise movement in said bracket, a pair of coil springsdisposed within said bracket, each of said coil springs surrounding aportion of and engaging a respective one of said first and second rodsto spring bias said rods in the same direction, an abutment membermounted upon said second rod, a trip-member carried by said bracket, anda latch-supporting block rigidly mounted upon said first rod; theimprovement which consists in the provision of a bifurcated latch memberpivotally engaging said first rod in spaced positions and surroundingsaid latchsupporting means, said member being shiftable about thelongitudinal axis of said first rod, and a leaf spring having one endsecured upon said member and the other end thereof engaging saidlatch-supporting block to spring bias said member against said secondrod and in engagement with said abutment member.

2. A safety device of the class described, comprising a C-shapedbracket, the arms of said bracket being bearing members, a firstand asecond rod mounted for endwise movements within said bearing members andbeing disposed in parallelism with each other, a pair of coil springsdisposed between said bearing members, each of said coil springssurrounding a portion of and engaging a respective one of said first andsecond rods to spring bias said rods in the same direction, a blocksecured upon said first rod, a bifurcated latch member pivotallyengaging said first rod in spaced positions and embracing two opposingsides of said block so as to be shiftable about the longitudinal axis ofsaid first rod, an abutment member secured upon said second rod, a leafspring disposed lengthwise of said latch member and having one endthereof secured upon said latch member and its other end engaging saidblock to spring bias said latch member toward said second rod and inengagement with said abutment member, and a trip-member fixed upon theside of said bracket to be engaged by said latch member for pivoting thelatter about the axis of said first rod in opposition to said leafspring thereby to disengage the latch member from said abutment memberupon a prede- 10 termined movement of said first rod.

MICHAEL MCCANN.

